The idea of distant supervision [1]} eliminates the need for manual annotation for obtaining training data for relation extraction. Previously, this idea is used mostly to create sentence-level datasets. However, the assumption of distant supervision, that the two entities of a tuple must appear in the same sentence, is overly strict. We may not find an adequate number of evidence sentences for many relations as both entities do not appear in the same sentence. The relation extraction models built on such data can find relations only for a small number of relations and the relations of most knowledge bases (KBs) will be out of the reach of such models.
